According to the WSJ, thousands of instant messages were uncovered using search warrants and in cooperation with Canada smartphone company BlackBerry. The communication helped authorities make key connections between alleged money launderers and supposed clients, which included lawmakers and construction contractors.

So far more than 100 people have faced criminal charges, the WSJ says, and the investigation has included nearly 50 Brazilian politicians. The probe is called "Operation Car Wash" and has had a huge impact on the country's establishment and Petrobras, which largely deals with oil.

One BBM message feed covered meetings, cash pickups, and bank transfers relating to deals. It's all to do with allegations that high-flying execs, politicians, and other officials have been skimming hundreds of millions of dollars from the state-controlled Petrobras oil giant.